Abstract

The on-site generation and direct consumption of electricity, so-called self-consumption, with a combined photovoltaic (PV) and battery storage system is becoming increasingly profitable for private households. The profitability of PV self-consumption system largely depends on the match of PV output and the household’s electricity consumption. In energy system modelling, the household’s consumption behaviour is represented by means of a standard load profile. However, the household sector’s heterogeneity is not reflected in one single profile, and the use of only one load profile results in a misjudgement of the profitability of self-consumption. In this study, we present a set of representative household groups that better represent the heterogeneous residential consumption behaviour. The household groups were compiled through the cluster analysis of smart-meter data based on hourly electricity consumption, using household characteristics as explanatory variables. Between the average load profiles of the groups, significant differences were found. Subsequently to the clustering, self-consumption based on a combined PV and battery system was simulated for each household. We found that the achievable level of self-consumption also differs between the groups, which in turn affect the profitability of the PV and battery systems. A statistical analysis revealed that employment and the presence of children are distinguishing factors for the different types of self-consumers. These results suggest that (i) the residential sector is not well represented by a single standard load profile, particularly so in the context of self-consumption modelling. (ii) Different self-consumer types can be identified through socio-demographic characteristics: We found that unemployed households achieve the highest self-sufficiency rates with an average of 40%, the lowest rates with 30% on average occur within households of educated families. (iii) Although the discrepancies are significant, the effect of these differences on profitability is still limited under the current market conditions.

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Acknowledgements

This work has been financially supported by the German Federal Ministry for Economic Affairs and Energy in the context of a project “Flexible Nachfrage als wichtiger Beitrag zur Energiewende und Baustein in der Energiesystemanalyse” as a part of the 6. Energieforschungsprogramm. Additionally, we would like to thank Tobias Fleiter, Jan Kersting and Katharina Wohlfarth for their input and valuable discussions.